The embodiments described herein relate generally to electrical power transmission systems and, more particularly, to systems and methods for analyzing oscillatory stability in electrical power transmission systems under the effects of a plurality of postulated fault conditions, i.e., “contingencies,” that cause perturbations in the system.
Power transmission systems are subject to system perturbations during events such as, for example, line faults, changes in generation, or changes in load demand. Such changes in the system may cause stability problems for the system in many different respects, such as voltage stability, i.e., the system's ability to maintain steady voltage, frequency stability, i.e., the system's ability to maintain steady frequency, and oscillatory stability, i.e., the system's ability to maintain a steady state operating point.
To analyze small perturbations in power transmission systems with respect to oscillatory stability, some known methods create a mathematical model of the system that represents the various elements of the system. With the mathematical model, a number of contingencies are analyzed using time-domain simulations of the system under the effects of the contingencies. However, in large systems, there are a large number of possible contingencies. Time-domain analysis of each contingency is computationally intensive and not feasible in short time periods such as may be required during real-time operational management. One known general approach to contingency analysis involves “screening and ranking,” in which a large number of contingencies are filtered out, and only a select few contingencies are analyzed in detail. However, to generate sufficient results by screening and ranking contingencies, the most critical contingencies must be identified for full analysis.